Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

How peroxisomes formed, How Peroxisomes formed Peroxisomes are formed w...

How Peroxisomes formed Peroxisomes are formed within the cell from the smooth endoplasmic reticulum by a process of budding. Peroxisomes found in the kidney and liver cells are

What are the main risk factors for hypertension, Q. What are the main risk ...

Q. What are the main risk factors for hypertension? The major risks factors for hypertension are tobacco smoking, stress, obesity, sedentary lifestyle and alcoholism.

What are antioxidants, What are antioxidants? To put it simply, antioxi...

What are antioxidants? To put it simply, antioxidants are important naturally occurring nutrients, (vitamins, minerals) which help to protect body from certain types of cancers

Cessation of spontaneous body functions, A person is declared to be dead up...

A person is declared to be dead upon the irreversible cessation of spontaneous body functions; brain activity, or blood circulation and respiration. However,only about 1% of a pers

What are the hexoses, Q. What are the hexoses? What are some examples of he...

Q. What are the hexoses? What are some examples of hexoses with vital biological functions? Hexoses are carbohydrates whole of six carbons. Galactose, fructose and Glucose are

Gonads and ovary - reproduction, Normal 0 false false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Determine periimplant sulcus fluid analysis, Periimplant Sulcus Fluid Analy...

Periimplant Sulcus Fluid Analysis (PISF) This is not a parameter for clinical use but for experimental situations. However, it is important for us to know about it. Several bio

How substrate concentration affect the enzymatic reaction, How does the sub...

How does the substrate concentration affect the speed of enzymatic reactions? Initially as substrate concentration increases, the speed of the reaction enhances; this happens b

Invertebrates, Are chaetopterus species coelomate?

Are chaetopterus species coelomate?

Venous drainage of the heart, The coronary sinus is the main vein of the he...

The coronary sinus is the main vein of the heart and is about 3 cm. long. It lies in the coronary sulcus at the posterior surface of  the heart in the posterior atrio-ventricular g

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd